Method of testing eyes and apparatus therefor



B. W. KELLY May 18, 1937.

METHOD OF TESTING EYES AND APPARATUS THEREFOR Filed May 27, 1932 INVENTOATTORNEYS.

Patented May 18, 19s? 2,080,721

UNITED STATES PATENT OFFICE METHOD OF TESTING EYES AND APPARATUSTHEREFOR Benjamin W. Kelly, Des Moines, Iowa, assignor to Keystone ViewCompany, Meadville, Pa., a corporation of Pennsylvania Application May27, 1932, Serial No. 613,878

Claims. (Cl. 88-20) In the examination of eyes it is desirable to inthis portion of the fused field, thus indicating test the eyes invarious ways for various weakthe defect in the eye. These spots mayappear at nesses. The present invention is designed to the center,around the margin, or eccentric to the simplify some of these tests. Innearly all perfield of vision, depending upon the position of 5 sons oneor the other eye is more or less dominant. the blind spot on the retina.5 In many eyes there are blind spots, or portions Where there is verylittle vision in one eye there of the retina that have no vision. Theseblind may be no fused field apparent when the two colspots may be in thecenter of the retina, may be ored slides are used, as indicated above.The in concentric zones or at different points in the fusion may bestimulated by more or'less rapid l0 retina. In carrying out my inventionI use a motion of the colored slide before the defective special form ofstereoscope and place before each eye, or by slowly moving the twoslides back and eye specially selected and prepared slides of difforthacross the slide holder so that the inner ferent colors, preferablycomplementary colors, so ends of the slides, which should touch eachother, placed that light from only one colored slide may appearalternately before each eye, thus may enter each eye, or by certainmovements of stimulating by motion and contrast, the nerve 15 theslides, two colors may be made to enter endings of the defective retina.each eye, if desired. Where the eyes are normal In some individuals withone eye decidedly dethese colors blend so that the observer sees afective there is a defect in the fusion faculty single color which is ablend of the two. If the which alows them to perceive only the generaltwo colors are exactly complementary, the obsensation of color in thefusion field, as above served blended color will be a neutral grey. Ifdescribed, and it is highly desirable to discover one eye is slightlydominant the fused color will whether such a patient can fuse ondefinite forms be tinted by the color entering the dominant eye. as wellas on colors over the entire field.

Should the portion of the retina most sensitive As a test for such acondition, I have designed to light, called the yellow spot or maculalutea slides of such forms and colors that, when introbe partiallydefective in one or both eyes while the duced into the slide holder of aproperly conremainder of the retina, or so-called peripheral structedstereoscope, the patient will see, if senregion is normal the blendedcolor will appear to sitive to form fusion, certain shapes which vary begrey over the edges of the field of vision only as the slides arebrought nearer together or while the center of the field will be tintedwith farther apart in the slide holder. For example 30 one or the otherof the colors, depending upon a pair of slides with semicircular ends,one being which eye is most nearly perfect in the macular blue, theother its complementary yellow, when region. On the other hand, if theperipheral repushed toward each other in the slide holder, apgicn ofeither or both eyes should be defective pear to first overlap, then toform a grey circle while the macular regions are normal, the edges orball, and finally to form an oblong grey figure. 35 of the field ofvision will be tinted with one or This will be true only if both eyesare sensitive to the other of the colors while the central portion form.If one eye is defective in this regard, only of the field will appear tobe grey. Where there a blurred figure, or a general sensation of coloris no sight whatever in some portion of either will be apparent to thepatient.

retina, whether it be in the macular region, or I have illustrated inthe accompanying draw- 40 the peripheral region, the defect will cause aing a stereoscope according to my invention and definite colored spot toappear in the blended which is adapted for the practice of the methodgrey field in a position and of a size corresponding as follows:- to theposition and size of the actual blind spot Fig. 1 shows a plan view of astereoscope, partly in the retina. in section. 45

For example, where there is a blind spot in the Fig. 2 an elevation ofthe view holder with views right eye and a blue slide is used before theright therein. eye and its complementary yellow before the left Fig. 3 afused field as it appears to a user haveye, the fused field will appearas a neutral gray ing an eye defect.

except for a definite yellow spot corresponding Fig. 4 a similar viewshowing aslightly different 5 in size and position to the blind spot inthe right defect. retina. That is to say, the blue which falls upon Thestereoscope has lenses I, a visor 2, barrels the blind spot of the rightretina is not fused with 3, and field plates 4. A telescopic guide 5 issethe yellow falling upon the corresponding normal cured to the barrelsand a view holder 6 is mountspot on the left retina so that only yellowappears ed on the guide. The view holder has under-cut 55 guide slots 1at its top and bottom adapted to receive views, such as S and 9. Theseviews, as shown, are yellow and blue, but it will be understood that anydifferent, or complementary colors, may be used, the response ofdifferent eyes to different colors differing somewhat. These views havethe semi-circular extending ends 8a and 9a respectively at one end andpointed projections 8b and 1) at the opposite ends.

In the use of the stereoscope, as above described, the views are placedin the holder and observed by the user, and the fusion, or lack offusion reported. If there is a lack of fusion, the dominant eye willimmediately be manifest through the color response of the patient, andthe other eye may be stimulated by more or less vigorous movements ofthe slides in front of it, or by a back and forth motion of both slidesso that each eye may alternately see each color.

The patient may also be examined as to his response to form by adjustingthe views, one to the other. When properly adjusted if there is responseto: fusion and to form the semi-circular parts 8a and 9a complement eachother so as .to give the effect of a circle, as l0, having the fusedcolor. In similar manner, the extending points 81) and 9b when arrangedat the center may be adjusted to give the fused effect of a diamondform. These narrower and preferably tapered projections on the views areof particular advantage in determining the location of defectsrelatively to the macula lutea portion of the retina, or the so-calledperipheral regions.

Not only is lack of response of one eye, or the other, indicated, bothas to color and form, but color blindness and lack of form sensitivenessin one, or the other eye, is, of course, immediately manifest and theeye having such blindness indicated. Blind spots are also indicated, asfor instance, if there is a blind spot in the center of the left eye theyellow in the fusion will be absent from the blind spot and a blue spotH, as indicated in the fused portion l0, Fig. 3, will appear. Likewise,if there is a blind spot in the right eye away from the center of theretina a yellow area II will appear in a corresponding position in thefused field. In this way, many defects of the eyes may be very promptlydetected.

What I claim as new is:-

1. The method of testing eyes which consists in presentingstereoscopically individually to each eye views having reflectedsubstantially solid color fields of different colors, the adjacentportions of the views being provided with extensions of smaller areathan the main portion of the views, and noting for diagnosis theresulting fusions for eye defects in the remaining portions of thefields.

2. The method of testing eyes which consists in presentingstereoscopically individually to each eye views having reflectedsubstantially solid color fields of different colors, the adjacentportions of the views being provided with extensions of smaller areathan the main portion of the views, and noting for diagnosis theresulting fusions, and varying the relation of the adjacent portions ofthe fields to form a fusion overlap distinct from the remaining portionsof the fields.

3. The method of testing eyes which consists in presentingstereoscopically individually to each eye views havingrefiectedsubstantially solid color fields of different colors, the adjacentportions of the views being providedwith extensions of smaller area thanthe main portion of the views, and noting for diagnosis the resultingfusion, and varying the relation of the adjacent portions of the fieldsto form a fusion overlap distinct from the remaining portion of thefields and varying the fusion overlap.

4. An eye testing device comprising a stereoscope; and complementaryviews, the adjacent portions of which are provided with extensions ofsmaller area than the main portion of the views, said views havingreflected substantially solid color fields of different colors, saidfields having a fusion overlap increasing in width from the adjacentedges and extending only through a portion of the fields.

5. An eye testing device comprising a stereoscope; and complementaryviews, the adjacent. portions of which are provided with extensions ofsmaller area than the main portion of the views, said views havingreflected substantially solid color fields of different colors, saidfields having a fusion overlap of at least a portion of the fields; andmeans varying the views to vary the extent of the overlapping fusionwhereby the degree of color sensitiveness of the eye may be measured.

BENJAMIN W. KELLY.

